Executable programs, and files requiring executable programs to open, are available in all forms to computer users from many sources. Not only can such programs be downloaded from remote locations such as the cloud or other computers in a local area network, but they can be purchased at retail stores and provided by other computer users on computer-readable media such as compact discs (CDs) and DVDs. One problem with such programs, especially those obtained or purchased from other than well known vendors, is that any such program can pose a threat to the user's computer. For example, a user can launch such a program and unknowingly infect his or her computer with a virus or other malware. Often, malware is even disguised as another program in an attempt to deceive users into believing that it is safe to install the program on their computers.
Various approaches have been proposed for checking the reputation of files downloaded from the Internet. While these approaches may be convenient and effective when applied to downloaded files it would be advantageous to be able to check executable programs at the time a user enters a command to a computer's operating system software to launch the program, but before the program is actually run.